Effect of the bread‐baking process on destruction of certain mould spores

Abstract

Because of conflicting statements in the literature, experiments have been camed out in which spores of moulds commonly associated with mouldy bread have been incorporated in bread doughs before baking. It has been demonstrated that such moulds and the ascospores of Neurospma tetrasperma are killed well before the end of the baking period. This evidence supports the contention that in normal bakery practice moulds do not survive baking and that mould growth on bread is due t o post-baking contamination with mould spores. IntroductionThe wastage of bread due to the development of mould costs the baking industry a large s u m of money each year, one estimate' being that the equivalent of about five million IQ-lb. loaves are spoiled in this way per annum. This mould problem, which occurs mainly in the summer months, is most serious in the case of sliced, wrapped bread where conditions for the development of mould spores are rather more favourable than with unwrapped loaves.At the present time, mould inhibitors are not permitted as bread additives in this country (but see reference 2), although the use of such inhibitors would result in a significant reduction in the wastage of bread due to mould growth. Nevertheless, it is important to remember that anti-mould agents normally delay rather than prevent the development of mould' and that, while bread spoilage will be reduced if mould inhibitors are permitted as additives, mould is likely to remain a problem in the baking industry.It is generally considered that post-baking contamination of bread by mould spores is the origin of the moulds that subsequently develop on the bread. While the mouH spore population of air is variable and is affected by such factors as the time of year and the location,s and by the conditions in the bakery, it is clear that, unless stringent precautions are taken, post-baking contamination of bread by air-borne mould spores will be significant. For example, it has been estimated that some 7000-8000 mould spores per sq. m. of surface may settle from the bakery atmosphere in an hour.' Under normal circumstances, therefore, mould will develop on bread if the storage conditions are suitable.Despite the inevitable danger of post-baking contamination, it is important to establish whether mould spores present in the dough ingredients wiU survive the baking process. Flour always contains mould spores which are mainly derived from the wheat from which it has been milled, although contamination can occur during the milling p r o c e~s .~ A number of workers have measured the mould spore population of flour and have obtained results varying within wide limits. Mould spore counts obtained in these laboratories in recent years have ranged from 500 to 70,000 per g. (average goo0 per g.) and these results are considered to be typical.The conditions prevailing when bread is baked are such that, from these considerations alone, it is extremely unlikely that mould spores in the dough would survive the baking process. Bread is usually baked at oven temperature...

Oxidative and Microbial Stability of Pomegranate Peel Extracts and Bagasse Supplemented Cookies

“…Baking process primarily destroys potential pathogens and minimizes microbial food spoilage factors. However, baking at lower temperature, mishandling during packaging, cross contamination and improper food storage sound to be the potential factor that may change the safety and quality status of the baked goods (Knight and Menlove 1961;Saranraj 2012).The data presented in Table 3, indicate least to no aerobic counts identified on growth medium plates and inoculated with samples prepared from Pbg and PoPx supplemented cookies. A nonsignificant difference of total aerobic counts and yeasts/ molds was recorded in cookies supplemented with 1.5-4.5% Pbg whereas a significant reduction in microbiological load was noticed in the treatments carrying 6.0-7.5% Pbg and 0.25-1.0% PoPx.…”

Impact of Storing Condition on Staling and Microbial Spoilage Behavior of Bread and Their Contribution to Prevent Food Waste

“…The intrinsic composition of bread (≈40%( w / w ) water content, pH = 5.5–6.0 and an a w -value within 0.94–0.97) facilitates fungal growth [ 9 ]. As spores are commonly considered to be inactivated during the baking process [ 10 ], contamination generally arises from the surrounding air, machines, workers (production and sale), the consumer or the storage environment [ 9 , 11 , 12 ]. Such contaminations lead to fungal growth, which can result in undesired changes causing consumer rejection due to the development of mycelium or the accumulation of mycotoxins in the bread matrix, which can cause adverse health outcomes involving carcinogenic or genetically harmful effects [ 13 ].…”

Microbial characterization of discarded breads

“…Since all the samples tested had E. coli counts below the LOQ, these results are not shown in the tables. Due to the baking process, most of the microorganisms present in bread are thermally destroyed (Knight & Menlove, 1961). Therefore, the microbial contamination observed must be caused by recontamination after baking.…”